My DH and I went last summer on a very good package deal through Sceptre Tours. They have some very good deals on fly/drive as well as Dublin visits. We took Aer Lingus out of JFK, but took Delta Shuttle to JFK vs. the long layovers in Boston. I'm in the hotel industry and the package we got was better than anything I could find even with my connections.
http://www.sceptretours.com/